1. Field of the invention
This invention is concerned with vortex tubes. More particularly, the present invention relates to a manufacture using a method of a vortex tube design, which provides a vortex tube having a high efficiency by eliminating of any freeze up during operation.
2. Description of the Prior Art
A vortex tube comprises a slender tube with a diaphragm closing one end of the tube provided with a discharge hole in the center of the diaphragm, one or more tangential inlet nozzles piercing the tube just inside of the diaphragm and, depends on the vortex tube's desirable performance, a controlled discharge opening (throttle valve) or plug (U.S. Pat. No. 5,911,740) on the other end of the slender tube.
In the vortex tube an inlet high-pressure gas flow undergoes energy separation forming two low-pressure currents: cold and hot. Under some circumstances a cold fraction discharged from the vortex tube through the diaphragm opening may freeze up and reduce the diaphragm orifice, thus causing the vortex tube's performance deterioration.
It is known to use a vortex tube's hot fraction to prevent discharge diaphragm freeze up. At this point a hot flow taken prior to or after the throttle valve is directed to the heat exchanger attached to the outward side of the diaphragm (U.S. Pat. No. 5,749,231) or, according to the U.S. Pat. No. 5,937,654, a hot flow circulates in the heat transfer body coinciding with outward of the vortex tube's cross section.